Low Carbon Homes

Masonry can be used to deliver the lowest carbon homes. For example the PassivHaus standard which concentrates purely on energy performance (and hence operations CO2 emissions) has many examples of masonry buildings ( PassivHaus applies to domestic and non-domestic buildings).

The move towards low carbon homes in recent years has seen a steady improvement in the fabric energy performance of masonry construction, which can easily meet or exceed Part L requirements. This applies to a broad range of masonry products/systems.

Energy performance

The enhanced fabric energy performance of masonry construction has been achieved through a range of measures including higher standards of insulation, airtightness and thermal bridging. However, one property that remains unaltered is masonry’s inherent thermal mass, which can boost the performance of low energy heating systems and also provide some useful resilience to the growing problem of overheating in new homes.

The energy performance of new masonry buildings can meet and exceed minimum requirements. Achieving required or desired energy performance arises from good design and construction in the following areas: U-values of elements, thermal bridging at junctions and air tightness. In addition thermal mass can play a role in winter energy performance and in summer avoidance of overheating and the desire for airconditioning.

Embodied carbon comparison

The NHBC Foundation did a comparison of the embodied carbon of masonry and timber homes and found the difference to be less than 5 per cent. This supports research by ARUP which concluded the same with respect to embodied carbon but also looked at operational carbon. It found that the small additional embodied carbon of a masonry home compared with a timber home was offset in only 11 years. Therefore over a lifetime of 10 times this – 110 years - the carbon savings during operation are ten times more significant than the small additional carbon at build stage.